Such a device and such a method are known from DE 3 218 886 C1. In this context, the stud to be welded to a component is conveyed by compressed air through a feed channel through an elastically expandable chuck until it contacts a movable stud stop that is located on the workpiece side on the device housing in front of the chuck. The stud is positioned correctly in the chuck by the stud stop. To close the chuck, a tubular actuator is pushed onto the chuck toward the stop by a pneumatic working cylinder, wherein mutually corresponding angled ramps produce the radial closing motion. The chuck can be moved axially to a limited extent by motor drive, and in its movement to the welding position it pushes the movable stud stop to the side so that the stud is freed for welding. A disadvantage of the known method and the known apparatus is the long axial stroke of the chuck and the relatively complicated construction resulting from the movable stud stop.
In the prior art, the welding stroke motion in short cycle arc welding is generally performed by a linear motor drive, while the advancing motion of the welding head as a whole toward the component is generally performed by a pneumatic drive such as a cylinder. It is disadvantageous here, firstly, that no regulation of any sort can take place, and secondly, that lines for the compressed air must be routed through the cable assembly and through the welding head.